I have an OS46 FXi that came with the NexStar. It came with an 11x5 prop but my instructor said to switch to APS 12.25x3.75. I am having a terrible time getting it to throttle up from low to high without the engine cutting out. We have followed bubbagates recommentdations on setting high speed and low speed. I keep moving low speed very minimally too. We are running it slightly rich to rich. I have run 1 1/2 gals. through it so far. We are only getting 9 mins. on 12 oz. tank and my instructor dead sticks a lot when it cuts out. We find that the prop stops nearly verticle and you have to break it free with slight pressure. Sounds like it is binding. Instr. says it may be extremely tight engine but when it breaks in it will be the best engine I'll ever have. Everyone else says it should only take 2 or 3 TANKS to fully break in an OS. Another member has a NexStar same as mine, and his engine runs great. He has never had any problems. He has same instructor and same fuel.

THERE IS A QUESTION IN HERE. SHOULD I GO BACK TO THE 11X5 PROP? I TALKED TO OS AND THEY SAID TO SHIP IT BACK TO THEM (WITH NO GUARANTEE) - BUT THEN I WON'T HAVE ANYTHING TO FLY.